For an efficient use of resources of a wireless telecommunication system smart antenna systems attract more and more attention. Generally, co-located with the base station, a smart antenna system combines an antenna array with a digital signal-processing capability to transmit and receive signals in an adaptive, spacially sensitive manner. In other words, such a system can automatically change the directionality of its radiation patterns in response to its signal environment. This can dramatically increase the performance characteristics such as the capacity of the system.
To obtain these benefits a smart antenna array has to be calibrated. In the prior art a separate antenna being located at a well-known location is used for this purpose. This extra antenna sends beacon signals to the antenna array and receives signals from the array. By an analysis of changes in the phase and the amplitude of the signals the individual antennas of the antenna array can be calibrated.